The present invention relates to magnetic hard disk drives. More specifically, the present invention relates to a system for damage prevention by improving the shock resistance of a hard disk actuator arm.
There are several types of computer data storage devices. One is a hard disk drive (HDD). The HDD utilizes one or more magnetic disks to store the data and one or more heads to read data from and write data to the disk(s). As advances have occurred in the art of hard drive and other computer technology, hard drives and their associated computer systems have become small enough to enable portability. Along with the portability of such systems, comes an increased risk of shock or vibration causing either impaired read/write ability or damage to the hard drive.
If a hard drive experiences severe vibration or mechanical shock, the actuator arm, which positions the head over the magnetic disk, may impact the disk, potentially damaging either the head or disk or both. In addition, damage may occur to components such as the arm suspension and physical and electrical connections. Further, if a micro-actuator system is utilized for fine-tuning of head placement, damage could occur to the micro-actuator itself. In the art today, different methods are utilized to prevent such damage.
FIG. 1 illustrates a typical method utilized to prevent damage caused by shock or vibration to a hard drive. A stationary ramp 102 is located near the outer edge of the disk 104. When the head 106 is moved beyond the edge of the disk, it rides onto the ramp 102, where it is ‘parked’ in a safe, restrained position. One problem with this design is that it is only effective during hard drive non-operation. It is unable to prevent damage during normal drive operation when the head 106 is reading data from and writing data to the disk 104. Further, a ramp 102 may only be used with ‘diagonal arm orientation’ hard drives 108, as shown in FIG. 1a. Because of space limitations, a ramp 112 may not be utilized with ‘perpendicular arm orientation’ hard drives 110, as shown in FIG. 1b. 
FIG. 2 provides an illustration of another method of preventing shock/vibration-associated damage, which involves the utilization of a stationary ‘comb’. As shown in FIGS. 2a (top view) and 2b (side view), the comb 206 is affixed to the hard drive casing 212 in a location such that each of the disks 202 and each of the arms 204 has a position interposed between ‘teeth’ 208 of the comb 206 throughout the arm's 204 range of motion (See FIG. 3, also).
FIG. 3 provides another illustration of the ‘comb’ method of arm stabilization. FIGS. 3a and 3b show the arms 304 at the opposite end of their range of motion 314. One disadvantage of the ‘comb’ method is that there is a substantial portion (the load beam 316) of the arm 304 that is unconstrained by the comb 306. This portion 316 of the arm is free to move toward and away from the disk 302 under vibration or mechanical shock in a ‘spring-like’ manner. Another disadvantage is that the comb 306 supports only the base plate portion 318 of the arm and not the suspension (load beam 316) of the head 320 (discussed below). Further, the distance from the support of the comb 306 to the head 320 is relatively large, allowing for substantial displacement of the head under shock/vibration. It is therefore desirable to have a system for improving the shock resistance of a hard drive actuator arm in addition to other advantages.